<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Feed_Reader
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Feed.php 23775 2011-03-01 17:25:24Z ralph $
 */

/**
 * @see Zend_Feed_Reader_Extension_FeedAbstract
 */
require_once 'Zend/Feed/Reader/Extension/FeedAbstract.php';

/**
 * @see Zend_Date
 */
require_once 'Zend/Date.php';

/**
 * @see Zend_Uri
 */
require_once 'Zend/Uri.php';

/**
 * @see Zend_Feed_Reader_Collection_Author
 */
require_once 'Zend/Feed/Reader/Collection/Author.php';

/**
 * @category   Zend
 * @package    Zend_Feed_Reader
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Feed_Reader_Extension_Atom_Feed extends Zend_Feed_Reader_Extension_FeedAbstract {
	/**
	 * Get a single author
	 *
	 * @param  int $index
	 * @return string|null
	 */
	public function getAuthor($index = 0) {
		$authors = $this->getAuthors ();
		
		if (isset ( $authors [$index] )) {
			return $authors [$index];
		}
		
		return null;
	}
	
	/**
	 * Get an array with feed authors
	 *
	 * @return array
	 */
	public function getAuthors() {
		if (array_key_exists ( 'authors', $this->_data )) {
			return $this->_data ['authors'];
		}
		
		$list = $this->_xpath->query ( '//atom:author' );
		
		$authors = array ();
		
		if ($list->length) {
			foreach ( $list as $author ) {
				$author = $this->_getAuthor ( $author );
				if (! empty ( $author )) {
					$authors [] = $author;
				}
			}
		}
		
		if (count ( $authors ) == 0) {
			$authors = null;
		} else {
			$authors = new Zend_Feed_Reader_Collection_Author ( Zend_Feed_Reader::arrayUnique ( $authors ) );
		}
		
		$this->_data ['authors'] = $authors;
		
		return $this->_data ['authors'];
	}
	
	/**
	 * Get the copyright entry
	 *
	 * @return string|null
	 */
	public function getCopyright() {
		if (array_key_exists ( 'copyright', $this->_data )) {
			return $this->_data ['copyright'];
		}
		
		$copyright = null;
		
		if ($this->getType () === Zend_Feed_Reader::TYPE_ATOM_03) {
			$copyright = $this->_xpath->evaluate ( 'string(' . $this->getXpathPrefix () . '/atom:copyright)' );
		} else {
			$copyright = $this->_xpath->evaluate ( 'string(' . $this->getXpathPrefix () . '/atom:rights)' );
		}
		
		if (! $copyright) {
			$copyright = null;
		}
		
		$this->_data ['copyright'] = $copyright;
		
		return $this->_data ['copyright'];
	}
	
	/**
	 * Get the feed creation date
	 *
	 * @return Zend_Date|null
	 */
	public function getDateCreated() {
		if (array_key_exists ( 'datecreated', $this->_data )) {
			return $this->_data ['datecreated'];
		}
		
		$date = null;
		
		if ($this->getType () === Zend_Feed_Reader::TYPE_ATOM_03) {
			$dateCreated = $this->_xpath->evaluate ( 'string(' . $this->getXpathPrefix () . '/atom:created)' );
		} else {
			$dateCreated = $this->_xpath->evaluate ( 'string(' . $this->getXpathPrefix () . '/atom:published)' );
		}
		
		if ($dateCreated) {
			$date = new Zend_Date ();
			$date->set ( $dateCreated, Zend_Date::ISO_8601 );
		}
		
		$this->_data ['datecreated'] = $date;
		
		return $this->_data ['datecreated'];
	}
	
	/**
	 * Get the feed modification date
	 *
	 * @return Zend_Date|null
	 */
	public function getDateModified() {
		if (array_key_exists ( 'datemodified', $this->_data )) {
			return $this->_data ['datemodified'];
		}
		
		$date = null;
		
		if ($this->getType () === Zend_Feed_Reader::TYPE_ATOM_03) {
			$dateModified = $this->_xpath->evaluate ( 'string(' . $this->getXpathPrefix () . '/atom:modified)' );
		} else {
			$dateModified = $this->_xpath->evaluate ( 'string(' . $this->getXpathPrefix () . '/atom:updated)' );
		}
		
		if ($dateModified) {
			$date = new Zend_Date ();
			$date->set ( $dateModified, Zend_Date::ISO_8601 );
		}
		
		$this->_data ['datemodified'] = $date;
		
		return $this->_data ['datemodified'];
	}
	
	/**
	 * Get the feed description
	 *
	 * @return string|null
	 */
	public function getDescription() {
		if (array_key_exists ( 'description', $this->_data )) {
			return $this->_data ['description'];
		}
		
		$description = null;
		
		if ($this->getType () === Zend_Feed_Reader::TYPE_ATOM_03) {
			$description = $this->_xpath->evaluate ( 'string(' . $this->getXpathPrefix () . '/atom:tagline)' ); // TODO: Is this the same as subtitle?
		} else {
			$description = $this->_xpath->evaluate ( 'string(' . $this->getXpathPrefix () . '/atom:subtitle)' );
		}
		
		if (! $description) {
			$description = null;
		}
		
		$this->_data ['description'] = $description;
		
		return $this->_data ['description'];
	}
	
	/**
	 * Get the feed generator entry
	 *
	 * @return string|null
	 */
	public function getGenerator() {
		if (array_key_exists ( 'generator', $this->_data )) {
			return $this->_data ['generator'];
		}
		// TODO: Add uri support
		$generator = $this->_xpath->evaluate ( 'string(' . $this->getXpathPrefix () . '/atom:generator)' );
		
		if (! $generator) {
			$generator = null;
		}
		
		$this->_data ['generator'] = $generator;
		
		return $this->_data ['generator'];
	}
	
	/**
	 * Get the feed ID
	 *
	 * @return string|null
	 */
	public function getId() {
		if (array_key_exists ( 'id', $this->_data )) {
			return $this->_data ['id'];
		}
		
		$id = $this->_xpath->evaluate ( 'string(' . $this->getXpathPrefix () . '/atom:id)' );
		
		if (! $id) {
			if ($this->getLink ()) {
				$id = $this->getLink ();
			} elseif ($this->getTitle ()) {
				$id = $this->getTitle ();
			} else {
				$id = null;
			}
		}
		
		$this->_data ['id'] = $id;
		
		return $this->_data ['id'];
	}
	
	/**
	 * Get the feed language
	 *
	 * @return string|null
	 */
	public function getLanguage() {
		if (array_key_exists ( 'language', $this->_data )) {
			return $this->_data ['language'];
		}
		
		$language = $this->_xpath->evaluate ( 'string(' . $this->getXpathPrefix () . '/atom:lang)' );
		
		if (! $language) {
			$language = $this->_xpath->evaluate ( 'string(//@xml:lang[1])' );
		}
		
		if (! $language) {
			$language = null;
		}
		
		$this->_data ['language'] = $language;
		
		return $this->_data ['language'];
	}
	
	/**
	 * Get the feed image
	 *
	 * @return array|null
	 */
	public function getImage() {
		if (array_key_exists ( 'image', $this->_data )) {
			return $this->_data ['image'];
		}
		
		$imageUrl = $this->_xpath->evaluate ( 'string(' . $this->getXpathPrefix () . '/atom:logo)' );
		
		if (! $imageUrl) {
			$image = null;
		} else {
			$image = array ('uri' => $imageUrl );
		}
		
		$this->_data ['image'] = $image;
		
		return $this->_data ['image'];
	}
	
	/**
	 * Get the feed image
	 *
	 * @return array|null
	 */
	public function getIcon() {
		if (array_key_exists ( 'icon', $this->_data )) {
			return $this->_data ['icon'];
		}
		
		$imageUrl = $this->_xpath->evaluate ( 'string(' . $this->getXpathPrefix () . '/atom:icon)' );
		
		if (! $imageUrl) {
			$image = null;
		} else {
			$image = array ('uri' => $imageUrl );
		}
		
		$this->_data ['icon'] = $image;
		
		return $this->_data ['icon'];
	}
	
	/**
	 * Get the base URI of the feed (if set).
	 *
	 * @return string|null
	 */
	public function getBaseUrl() {
		if (array_key_exists ( 'baseUrl', $this->_data )) {
			return $this->_data ['baseUrl'];
		}
		
		$baseUrl = $this->_xpath->evaluate ( 'string(//@xml:base[1])' );
		
		if (! $baseUrl) {
			$baseUrl = null;
		}
		$this->_data ['baseUrl'] = $baseUrl;
		
		return $this->_data ['baseUrl'];
	}
	
	/**
	 * Get a link to the source website
	 *
	 * @return string|null
	 */
	public function getLink() {
		if (array_key_exists ( 'link', $this->_data )) {
			return $this->_data ['link'];
		}
		
		$link = null;
		
		$list = $this->_xpath->query ( $this->getXpathPrefix () . '/atom:link[@rel="alternate"]/@href' . '|' . $this->getXpathPrefix () . '/atom:link[not(@rel)]/@href' );
		
		if ($list->length) {
			$link = $list->item ( 0 )->nodeValue;
			$link = $this->_absolutiseUri ( $link );
		}
		
		$this->_data ['link'] = $link;
		
		return $this->_data ['link'];
	}
	
	/**
	 * Get a link to the feed's XML Url
	 *
	 * @return string|null
	 */
	public function getFeedLink() {
		if (array_key_exists ( 'feedlink', $this->_data )) {
			return $this->_data ['feedlink'];
		}
		
		$link = $this->_xpath->evaluate ( 'string(' . $this->getXpathPrefix () . '/atom:link[@rel="self"]/@href)' );
		
		$link = $this->_absolutiseUri ( $link );
		
		$this->_data ['feedlink'] = $link;
		
		return $this->_data ['feedlink'];
	}
	
	/**
	 * Get an array of any supported Pusubhubbub endpoints
	 *
	 * @return array|null
	 */
	public function getHubs() {
		if (array_key_exists ( 'hubs', $this->_data )) {
			return $this->_data ['hubs'];
		}
		$hubs = array ();
		
		$list = $this->_xpath->query ( $this->getXpathPrefix () . '//atom:link[@rel="hub"]/@href' );
		
		if ($list->length) {
			foreach ( $list as $uri ) {
				$hubs [] = $this->_absolutiseUri ( $uri->nodeValue );
			}
		} else {
			$hubs = null;
		}
		
		$this->_data ['hubs'] = $hubs;
		
		return $this->_data ['hubs'];
	}
	
	/**
	 * Get the feed title
	 *
	 * @return string|null
	 */
	public function getTitle() {
		if (array_key_exists ( 'title', $this->_data )) {
			return $this->_data ['title'];
		}
		
		$title = $this->_xpath->evaluate ( 'string(' . $this->getXpathPrefix () . '/atom:title)' );
		
		if (! $title) {
			$title = null;
		}
		
		$this->_data ['title'] = $title;
		
		return $this->_data ['title'];
	}
	
	/**
	 * Get all categories
	 *
	 * @return Zend_Feed_Reader_Collection_Category
	 */
	public function getCategories() {
		if (array_key_exists ( 'categories', $this->_data )) {
			return $this->_data ['categories'];
		}
		
		if ($this->getType () == Zend_Feed_Reader::TYPE_ATOM_10) {
			$list = $this->_xpath->query ( $this->getXpathPrefix () . '/atom:category' );
		} else {
			/**
			 * Since Atom 0.3 did not support categories, it would have used the
			 * Dublin Core extension. However there is a small possibility Atom 0.3
			 * may have been retrofittied to use Atom 1.0 instead.
			 */
			$this->_xpath->registerNamespace ( 'atom10', Zend_Feed_Reader::NAMESPACE_ATOM_10 );
			$list = $this->_xpath->query ( $this->getXpathPrefix () . '/atom10:category' );
		}
		
		if ($list->length) {
			$categoryCollection = new Zend_Feed_Reader_Collection_Category ();
			foreach ( $list as $category ) {
				$categoryCollection [] = array ('term' => $category->getAttribute ( 'term' ), 'scheme' => $category->getAttribute ( 'scheme' ), 'label' => $category->getAttribute ( 'label' ) );
			}
		} else {
			return new Zend_Feed_Reader_Collection_Category ();
		}
		
		$this->_data ['categories'] = $categoryCollection;
		
		return $this->_data ['categories'];
	}
	
	/**
	 * Get an author entry in RSS format
	 *
	 * @param  DOMElement $element
	 * @return string
	 */
	protected function _getAuthor(DOMElement $element) {
		$author = array ();
		
		$emailNode = $element->getElementsByTagName ( 'email' );
		$nameNode = $element->getElementsByTagName ( 'name' );
		$uriNode = $element->getElementsByTagName ( 'uri' );
		
		if ($emailNode->length && strlen ( $emailNode->item ( 0 )->nodeValue ) > 0) {
			$author ['email'] = $emailNode->item ( 0 )->nodeValue;
		}
		
		if ($nameNode->length && strlen ( $nameNode->item ( 0 )->nodeValue ) > 0) {
			$author ['name'] = $nameNode->item ( 0 )->nodeValue;
		}
		
		if ($uriNode->length && strlen ( $uriNode->item ( 0 )->nodeValue ) > 0) {
			$author ['uri'] = $uriNode->item ( 0 )->nodeValue;
		}
		
		if (empty ( $author )) {
			return null;
		}
		return $author;
	}
	
	/**
	 * Attempt to absolutise the URI, i.e. if a relative URI apply the
	 * xml:base value as a prefix to turn into an absolute URI.
	 */
	protected function _absolutiseUri($link) {
		if (! Zend_Uri::check ( $link )) {
			if ($this->getBaseUrl () !== null) {
				$link = $this->getBaseUrl () . $link;
				if (! Zend_Uri::check ( $link )) {
					$link = null;
				}
			}
		}
		return $link;
	}
	
	/**
	 * Register the default namespaces for the current feed format
	 */
	protected function _registerNamespaces() {
		if ($this->getType () == Zend_Feed_Reader::TYPE_ATOM_10 || $this->getType () == Zend_Feed_Reader::TYPE_ATOM_03) {
			return; // pre-registered at Feed level
		}
		$atomDetected = $this->_getAtomType ();
		switch ($atomDetected) {
			case Zend_Feed_Reader::TYPE_ATOM_03 :
				$this->_xpath->registerNamespace ( 'atom', Zend_Feed_Reader::NAMESPACE_ATOM_03 );
				break;
			default :
				$this->_xpath->registerNamespace ( 'atom', Zend_Feed_Reader::NAMESPACE_ATOM_10 );
				break;
		}
	}
	
	/**
	 * Detect the presence of any Atom namespaces in use
	 */
	protected function _getAtomType() {
		$dom = $this->getDomDocument ();
		$prefixAtom03 = $dom->lookupPrefix ( Zend_Feed_Reader::NAMESPACE_ATOM_03 );
		$prefixAtom10 = $dom->lookupPrefix ( Zend_Feed_Reader::NAMESPACE_ATOM_10 );
		if ($dom->isDefaultNamespace ( Zend_Feed_Reader::NAMESPACE_ATOM_10 ) || ! empty ( $prefixAtom10 )) {
			return Zend_Feed_Reader::TYPE_ATOM_10;
		}
		if ($dom->isDefaultNamespace ( Zend_Feed_Reader::NAMESPACE_ATOM_03 ) || ! empty ( $prefixAtom03 )) {
			return Zend_Feed_Reader::TYPE_ATOM_03;
		}
	}
}
